Avoiding folder leakage/breakage during upgrade/re-JB?

OK, I have too many apps. Maybe 400. Most of them are in folders of course. I plan to upgrade from 4.0(jailbreakme.com) to 4.1 and re-JB with limera1n. I have springboard enhancements which let me get 20+ apps per folder: FolderEnhancer and FCSB. I also have infiniboard and infinidock. I have reduced all my folders to 12 items or less and my home pages to 16 items or less in preparation for removing these Cydia springboard tweaks and upgrading. I am hoping my folders will not burst open and overflow my pages with a tsunami of apps when I start doing this. I had this happen a couple of times during the early days of 4.0 and it was a real nuisance. Does anyone have any experiences to relate on this? (why do I have so many apps? Well, I keep track of when things are free for a few days and get them then, so most of my apps were free. nothing cracked.)

Update:
I wrote to Lance Fetters, the author of Folder Enhancer, the main springboard tweak I was worried about, and received this informative reply:

**************
Hi [lanulos],

On 10/15/2010 12:13 PM, [lanulos] wrote:
> I am wondering what will happen when I remove FE in prep for iOS
> upgrade/reJB. Will my folders still be there if I have reduced them
> all to 12 items or less? They won't break open and flood my
> springboard, will they?

Unfortunately it may, due to the current design of IconSupport. It's
rather complicated, but more or less it will revert to the icon state
that you used before installing IconSupport.

(I have submitted a patch to the IconSupport project to fix this kind of
issue, but unfortunately it is not ready for public release.)

Though I believe it will get synced automatically, you might want to
backup the following files:

/var/mobile/Library/SpringBoard/IconSupportState-*.plist

Then, after upgrading to 4.1, if you restore those files and install the
exact same set of IconSupport-using extensions that you used on 4.0
(i.e. FolderEnhancer, Infini*, Iconoclasm), it should restore the icon
layout.

Well, I bit the bullet and upgraded (see this post for my GreenPois0n experience and why I chose that instead of Limera1n). As to my many well-stuffed folders, basically they all went away, and then mostly came back.

Prior to upgrading, I synced (of course); then I removed FolderEnhancer (folders still there), and then Infiniboard, (folders seemed to go to an earlier configuration), and then I removed FCSB, at which all the folders burst releasing the tidal wave I had feared all along. I did the upgrade and re-jailbreak (see link above), and then I reinstalled FCSB and then Infiniboard, which got my overflowed, folder-free apps onto two very long pages. I figured I had a long process of re-foldering ahead of me. But then, I re-installed Infinidock. Astonishingly, most of my folders reappeared, with most their apps in them! An odd selection of apps was left out of the folders. Perhaps these were icons which were once the "excess" icons in folders tweaked to have more than 12 icons. I'm not quite sure. But I am pleasantly surprised to see that things have ended up semi-OK. But I can't figure out why Infinidock, which should only affect the dock and not the pages, should have restored the folders. It must have to do with quirks of IconSupport (see previous post).

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